A sports car that's fit for the family

"Other cars go whoopity, whoopity, whoopity; Mazda engines go hummmmm."

That was Mazda's claim to fame when it brought its full line of rotary-engine cars to the United States in the late 1960s.

After a long gap that hummmmm is back with the RX-8, Mazda's first four-seater sports car, and maybe the first real four-door sports car on the market. Mazda hopes the car will find a niche with parents of young kids who want a sports car, but still need practicality.

While the RX-8 compromises between those worlds, the trade-off works.

The overall package is small enough to offer nimble sports-car reflexes but big enough to accommodate children or adults in the back seat. The rear-hinged back doors have no central body pillars dividing them from the front doors. Entering the back seat looks easy, but passengers have to twist their feet around and poke them into a narrow opening behind the front seats.

Once in place, though, passengers find head and elbow room generous. Even the trunk is roomy, albeit with a mail-slit opening. If you're taking this car away for a weekend, pack in lots of small, soft-sided bags. Leave the Pullman luggage at home.

Much of the RX-8's agility and character come from its rotary engine, the first rotary sold in the US since the last RX-7 in 1995. That car was a racer's delight and today is prized among tuner cars - imports customized with rear spoilers, turbochargers, etc.

But for all its technical features and performance credentials, the $40,000 twin-turbo RX-7 was too expensive for a Mazda and it was pulled from the market.

At $27,000 well equipped, the RX-8 is more attractive. And it provides a welcome home for an innovative and intriguing engine technology.

The rotary engine, developed by German engineer Felix Wankel in the 1950s, has only three moving parts. An equivalent four-cylinder piston engine requires at least 22.

In theory, the rotary's simplicity should lead to better reliability, efficiency, and smoothness. But today's piston engines are still more reliable and efficient, given their big head start in development.

Where they can't match the rotary is in that legendary smoothness, low weight, and compact size. Those advantages make the rotary perfect for a small sports car. Without a lot of engine weight, the RX-8 feels light on its feet with quick reflexes and quick steering.

While it doesn't have the punch of a big-engine muscle car like the Corvette or the Nissan 350Z, the RX-8 drives so smoothly that 4000 r.p.m. feels like just loafing along. Still the car has plenty of reserve power, even with "only" 237 horsepower (versus the 250 originally advertised).

In the end, the RX-8 is a just-right sports car, with the right moves, few sacrifices, and a price that isn't out of line with its rivals. Now that's a tune you can hum all the way home.